Microstructure and characteristics of interpenetrating β-TCP/Mg-Zn-Mn composite fabricated by suction casting

A novel interpenetrating beta-TCP/Mg-Zn-Mn composite was fabricated by infiltrating Mg-Zn-Mn alloy into porous beta-TCP using suction casting technique. The microstructure, mechanical property and corrosion behaviors of the composite have been evaluated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), mechanical testing, electrochemical and immersion test. It was shown that the composite had a compact structure and the interfacial bonding between Mg-Zn-Mn alloy and beta-TCP scaffold was very well. The composite had an ultimate compressive strength of 140 +/- 20 MPa, which is near with the natural bone (2-180 MPa) and about 1000-fold higher than that of the original porous beta-TCP scaffold, and it still retained about two fifths of the strength of the bulk Mg-Zn-Mn alloy. The electrochemical and immersion tests indicated that the corrosion resistance of the composite was better than that of the Mg-Zn-Mn matrix alloy, and the corrosion products on the composite surface were mainly Mg(OH)(2), Ca-3(PO4)(2) and HA. (C) 2013 Elsevier Ltd. All rights reserved.